2003 Toyota Tacoma TRD Dbl Cab 4x4 SB. Small Coolant Leak from Overflow Bottle. Engine doesn't overheat or Temperature Gauge go past midway. Doesn't leak when driving/idling, ONLY after being driven

Could be as simple as the radiator cap, since you can drive all day then only leaks when shut off. The cooling radiator creates a vacuum to pull coolant from reservoir. If the cap is bad, it will spill out, or even just the hose fallen off between radiator and reservoir. But 'Blue Devil' is the only one the guarantees a 'permanent fix' for a head gasket. Sorry Doug, there is no magic potion in a bottle the will fix a blown head gasket, IF that is what's wrong. That crap is what is plugging up everything, think - a chemical goop circulating through you engine looking for holes to plug. Small water jacket passages, could have gummed up your thermostat.

Currently running NO Thermostat as Coolant will not circulate at all when it's in. Top hose will be scalding hot, bottom hose cool as can be!! Blue Devil is a liquid, NO chunks or "Goop" in it. I've watched the videos on YouTube and it seems to work magic on MAJOR Head Gasket leaks, warpage, even cracked blocks! Seriously, check it out on YouTube!! I can drive my Tacoma 100+ miles and it runs great. Pull in my driveway, open Radiator Cap and there is NO vacuum at all present! It sits for 3 - 5 minutes and there will be approx. a 1/2 cup of Coolant directly under the overflow tank. I got rear - ended a year ago and hit the SUV in front of me, smashed the rear AND front of my truck. $7,000+ in damage to my Tacoma!! I was looking the other night and the fins on the back of my Radiator are about 60% smashed flat due to hitting the fan in the wreck. They didn't replace my Radiator with new, only replaced AC Condenser. Personally, I am thinking Radiator, Water Pump, Timing Belt needing replaced. I'm @ 195,000+ miles now. S'posed to idle @ 650 rpm's but, it is now @ 500 rpm's. SO, I KNOW Timing Belt/Water Pump needs done. Wondering IF Head Gasket is fine, other parts are at fault? I am a decent mechanic and I believe it is running too damn good right now to be Head Gasket!! ALSO, when it was hot I pulled all Spark Plugs out and ALL are equally "dirty" but, they only have 4 - 5,000 miles on them. NO water/Coolant in oil or beads on dipstick, NO water/white "cream" on oil cap at all. I'm gonna replace Timing Belt, Tensioner, Water Pump as needed at current mileage. Going to also replace Radiator as I can get a new one for $70.00 and HOPE I fix the problem!! I'm Permanently Disabled, can't afford to pay $1,200 - $1,800.00 to have someone do my Head Gasket and it NOT be the problem but, I CAN afford the other parts and taking my time I can do the work myself. I don't have a garage at home but if I did, I could do the Head Gasket, IF needed! Also, the Thermostat I pulled out was a low dollar JUNK part. Gonna buy an OEM off eBay and see if that helps. Could just be simple fix. I've seen bad Thermostats new right out of the box in the past!! I appreciate ANY and ALL help and advice and THANK YOU!!!! Doug